We think of airplanes and automobiles as complicated mechanisms that require sophisticated design procedures. It's not surprising that the aviation and automotive industries pioneered computer-aided design in the 1960's. But window hardware?what's that? We wouldn't expect its designers to use a computer. However, as is often the case when one looks into a supposedly commonplace field, the design of window hardware is more challenging than one initially suspects. It turns out to involve, for example, the kinematic, dimensional, and force analysis of multilink mechanisms. These mechanisms are the key feature of casement windows, which pivot about a vertical axis, and awning windows, which pivot about a horizontal axis.